As the United States plugs into electric car technology, the question arises of whether electric vehicles are truly better for the environment than their gas-powered counterparts. Recent studies suggest that electrical cars do indeed create less harmful emissions into the atmosphere throughout their lifetime, but that these results depend largely on the changing environmental status of our country.

The production of electrical cars is more environmentally taxing than that of gas-powered cars, mostly because of the electric car’s unique battery. The lithium-ion battery maintains its lightness and longevity due to rare earth metals (like lithium) found deep in the ground. The process to retrieve these metals is damaging to the environment and inefficient. For instance, in certain rare earth metal mines in Jiangxi, China, workers poured ammonium sulfate into 8-feet deep holes to dissolve the clay and then showered their extracted dirt through acid baths. The remaining dirt was baked in a kiln, leaving the rare-earth metals, which amounted to 0.2% of the total clay originally extracted. The other 99.8% was dumped back into the ground. Although it is challenging to quantify the damage caused by rare-earth mining, many scientists estimate that an electric car’s production creates one ton more of emissions than the production of a gas-powered car. That said, it is possible to improve this efficiency with new innovations or with a larger demand for the rare-earth metals.

The efficiency of an electric car during its lifetime depends on the cleanliness of available energy. In the US, energy has been developed to be clean enough so that an electric car’s total emissions dip below those of a gas-powered vehicle after two years of use. To put the efficiency into some context, electric cars’ energy usage is equivalent to that of a 60-mpg car. Electric cars have become as efficient as a 200-mpg car in countries like Paraguay and Iceland, which are powered mainly by renewable resources. If the United States can harness this level of clean and affordable energy, our cars can be over nine times more efficient than our average gas-powered car.

When it comes time to dispose of the cars, studies are unclear as to which car has a more environmentally-friendly discarding. However, it is known that lithium-ion battery disposal thus far is not very efficient. As the business of electric cars progresses, vehicle production companies hope to devise a system of recycling their batteries for other cars, which can be instrumental in creating a clean life-cycle for our world’s transportation.